Clear SMI and non-evacuation candidate entries when filtering the slots buffer.

test/cctest/test-heap.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
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   CHECK(reinterpret_cast<void*>(buffer->Get(1)) ==
         HeapObject::RawField(heap->empty_fixed_array(),
                              FixedArrayBase::kLengthOffset));
   CHECK(reinterpret_cast<void*>(buffer->Get(2)) ==
         HeapObject::RawField(heap->empty_fixed_array(),
                              FixedArrayBase::kLengthOffset));
   delete buffer;
 }
 
 
+TEST(FilterInvalidSlotsBufferEntries) {
+  FLAG_manual_evacuation_candidates_selection = true;
+  CcTest::InitializeVM();
+  v8::HandleScope scope(CcTest::isolate());
+  Isolate* isolate = CcTest::i_isolate();
+  Heap* heap = isolate->heap();
+  Factory* factory = isolate->factory();
+  SlotsBuffer* buffer = new SlotsBuffer(NULL);
+
+  // Set up a fake black object that will contain a recorded SMI, a recorded
+  // pointer to a new space object, and a recorded pointer to a non-evacuation
+  // candidate object. These object should be filtered out. Additionally,
+  // we point to an evacuation candidate object which should not be filtered
+  // out.
+
+  // Create fake object and mark it black.
+  Handle<FixedArray> fake_object = factory->NewFixedArray(23, TENURED);
+  MarkBit mark_bit = Marking::MarkBitFrom(*fake_object);
+  Marking::MarkBlack(mark_bit);
+
+  // Write a SMI into field one and record its address;
+  Object** field_smi = fake_object->RawFieldOfElementAt(0);
+  *field_smi = Smi::FromInt(100);
+  buffer->Add(field_smi);
+
+  // Write a new space reference into field 2 and record its address;
+  Handle<FixedArray> new_space_object = factory->NewFixedArray(23);
+  mark_bit = Marking::MarkBitFrom(*new_space_object);
+  Marking::MarkBlack(mark_bit);
+  Object** field_new_space = fake_object->RawFieldOfElementAt(1);
+  *field_new_space = *new_space_object;
+  buffer->Add(field_new_space);
+
+  // Write an old space reference into field 3 which points to an object not on
+  // an evacuation candidate.
+  Handle<FixedArray> old_space_object_non_evacuation =
+      factory->NewFixedArray(23, TENURED);
+  mark_bit = Marking::MarkBitFrom(*old_space_object_non_evacuation);
+  Marking::MarkBlack(mark_bit);
+  Object** field_old_space_object_non_evacuation =
+      fake_object->RawFieldOfElementAt(2);
+  *field_old_space_object_non_evacuation = *old_space_object_non_evacuation;
+  buffer->Add(field_old_space_object_non_evacuation);
+
+  // Write an old space reference into field 4 which points to an object on an
+  // evacuation candidate.
+  SimulateFullSpace(heap->old_space());
+  Handle<FixedArray> valid_object =
+      isolate->factory()->NewFixedArray(23, TENURED);
+  Page* page = Page::FromAddress(valid_object->address());
+  page->SetFlag(MemoryChunk::EVACUATION_CANDIDATE);
+  Object** valid_field = fake_object->RawFieldOfElementAt(3);
+  *valid_field = *valid_object;
+  buffer->Add(valid_field);
+
+  SlotsBuffer::RemoveInvalidSlots(heap, buffer);
+  Object** kRemovedEntry = HeapObject::RawField(heap->empty_fixed_array(),
+                                                FixedArrayBase::kLengthOffset);
+  CHECK_EQ(buffer->Get(0), kRemovedEntry);
+  CHECK_EQ(buffer->Get(1), kRemovedEntry);
+  CHECK_EQ(buffer->Get(2), kRemovedEntry);
+  CHECK_EQ(buffer->Get(3), valid_field);
+
+  // Clean-up to make verify heap happy.
+  mark_bit = Marking::MarkBitFrom(*fake_object);
+  Marking::MarkWhite(mark_bit);
+  mark_bit = Marking::MarkBitFrom(*new_space_object);
+  Marking::MarkWhite(mark_bit);
+  mark_bit = Marking::MarkBitFrom(*old_space_object_non_evacuation);
+  Marking::MarkWhite(mark_bit);
+
+  delete buffer;
+}
+
+
 TEST(ContextMeasure) {
   CcTest::InitializeVM();
   v8::HandleScope scope(CcTest::isolate());
   Isolate* isolate = CcTest::i_isolate();
   LocalContext context;
 
   int size_upper_limit = 0;
   int count_upper_limit = 0;
   HeapIterator it(CcTest::heap());
   for (HeapObject* obj = it.next(); obj != NULL; obj = it.next()) {
@@ skipping 70 matching lines @@
   {
     SharedFunctionInfo::Iterator iterator(isolate);
     while (iterator.Next()) sfi_count--;
   }
 
   CHECK_EQ(0, sfi_count);
 }
 
 }  // namespace internal
 }  // namespace v8